ECOGENOTOXICOGICAL ASSESSMENTS OF SOME SELECTED FISH SPECIES FROM APODU RESERVOIR, MALETE, NORTH CENTRAL, NIGERIA
A.T. Anifowoshe, S.O. Oladipo, O.A. Owolodun, M.K. Akinseye, T.F. Olafimihan, A.G. Sidiq, A.A. Muhammed, T.A. Asa, and M.K. Mustapha (pp. 171-184)
Abstract
Increased agricultural and domestic activities around and within aquatic ecosystem could pose serious threats to the habitat quality and ichthyofauna diversity. Nigeria is a country notable for the alarming rate of water pollution. On the other hand, increased human populace around the Apodu Reservoir has led to an intensifying rate of pollutants’ influx into the water body. To date, there is limited information on the habitat quality and associated genotoxic effects of pollutants on physiology of fish communities from the Apodu Reservoir. To infer these, water samples were collected randomly, and fish species were assayed for genotoxicity using micronucleus and histological assays. In this study, the in situ genotoxic potential of different species of fish (Clarias gariepinus, Synodontis gambiensis, Saraetherodon galilaeus, and Protopterus annectins) present in the Apodu Reservoir on the somatic cells using MN assay was evaluated. The kidney, liver, and gills of the fishes (Clarias gariepinus, Auchenoglanis occidentalis, Tilapia mariae, Mormyrops deliciosus, Saraetherodon galilaeus, and Hemichromis fasciatus) found in the reservoir and the physicochemical parameters of both the reservoir and borehole water (negative control) were also examined. The physico-chemical and heavy metals analyzed (Ca > Ni > Cl > P > Mg > Fe > Zn > Mn > Cu > Pb = Cr) were below the proposed limit by standard organizations. The different species of fish thriving in the reservoir show varying level of micronuclei and nuclear abnormalities in the order (S. gambiensis > C. gariepinus > P. annectins > S. galilaeus), and the histopathological assessment of the kidney, liver, and gills amidst the fish shows mild alterations when compared to the control fish. The histopathology of the kidney of M. deliciosus shows severe changes amidst other species. The cortex in the renal tissue shows numerous glomeruli and tubules lying back to back and lined by cuboided epithelium cells. The livers of fish in the reservoir showed irregular plates of hepatocytes while the gills showed mild distortion of epithelia lining, cartilage, and lymphatic cells. The flowing of water alongside agricultural and domestic activities around the reservoir might be attributed to the micronuclei deformities and histopathological alterations. Proper management of the habitat quality of the Apodu Reservoir appears necessary.